(i) Technical Field
The present invention relates to focal-plane shutters and optical devices.
(ii) Related Art
Japanese Unexamined Patent Application Publication No. 09-179167 discloses a focal-plane shutter driving a blade by two arms.
To improve the shutter speed, it is contemplated that two arms are made of synthetic resins for reduced weight. In this case, the rigidity of the arms are reduced, so that the arms might flap in the optical axis direction when the blade stops after moving from a state of closing an opening to a state of opening the opening. This might damage the arms.